lithium diisopropyl amide 1) THF; 2) THF.; Yield given. Multistep reaction;

dihydrogen peroxide in acetone 2 h; Heating;

piperidine; acetic acid in benzene Mannich reaction; 54 h; Heating;

dihydrogen peroxide

1.1: n-butyllithium / tetrahydrofuran; hexane / -78 °C 1.2: selenium / tetrahydrofuran; hexane / -78 °C 1.3: 72 percent / tetrahydrofuran; hexane / -78 °C 2.1: 90 percent / aq. hydrogen peroxide; pyridine / 2 h / 20 °C 3.1: 85 percent / aq. hydrogen peroxide; pyridine / 144 h / 20 °C 4.1: 86 percent / aq. H2O2 View Scheme

1: 90 percent / aq. hydrogen peroxide; pyridine / 2 h / 20 °C 2: 85 percent / aq. hydrogen peroxide; pyridine / 144 h / 20 °C 3: 86 percent / aq. H2O2 View Scheme

1: 83 percent / n-BuLi, S8 2: 84 percent / Se, n-Bu-Li 3: 87 percent / H2O2 / pyridine 4: H2O2 / pyridine 5: H2O2 / pyridine View Scheme

1: 97 percent / aq. sodium periodate / acetone / a) 20 deg C, 16 h, b) reflux, 3 h 2: 1.) piperidine, 2.) p-TsOH / 1.) MeOH, reflux, 36 h, 2.) toluene, reflux, 60 h View Scheme